The present invention relates to a locking device comprising a lock latch which is movable between a first protruded lock position and a second withdrawn position, and a method for producing such a locking device.
Locking devices which are intended to combine to that a closing member, such as a cap, remains in a closed position are known in a countless number of different types. In one of its simplest shapes such a locking device consists of a flange directed downwards and arranged at, the front edge of the closing member, which flange is intended to be moved down in front of a wall of for example a case or a box of paperboard material, at which the closing member is arranged, said closing member being firmly hold against the wall by means of a pressure force and/or friction force between the flange and the wall. This type of locking device gives a very unsatisfactory locking effect simultaneously as it may be difficult to obtain a sufficient grip of the closing member and/or the flange when the closing member is to be opened. Locking devices which have been designed to offer a safe locking effect at cases or boxes for instance have generally received a very complex construction and/or have been difficult for a user to manipulate between a locking and a releasing position.
A first object with the present invention is to achieve a locking device, preferably for use in a closing member at a case or box construction, which gives a safe locking effect, i.e. in a safe way attend to that said closing member is held left in a closed position, simultaneously as the locking device may be manipulated in an easy way between a locking and a releasing position by the user.
A second object of the invention is to achieve a locking device which may be made of a light and inexpensive material simultaneously as it may be manipulated between a locking and a releasing position several times without being deformed in such an extent that it looses its locking capability.
A further object with the invention is to achieve a locking device which has a simple construction and may be produced in a rational way and with small expenses.
According to the invention said objects are obtained by means of a locking device described herein. A locking device constructed in accordance with the invention attains a safe locking capability in that the front part of the lock latch during action of a resilient force may be pushed into and held in a room of an object co-operating with the locking device. The arm easily accessible to the user, by means of which the lock latch is displaced between a lock position and a releasing position, contributes in that the locking device may be manipulated in an easy way between a locking and a releasing position by the user without the need of a big force.
According to a preferred embodiment one or more of the hinges that connect the parts included in the locking device are designed in such a way that they give rise to the resilient force which provides for that the lock latch is moved to the lock position and is held left in this lock position. By this, a force moving the lock latch is obtained in an easy and efficient way without the need of using separate springs or similar.
According to a particularly preferred embodiment of the invention, the arm has a length between a first and a second hinge which is longer than the length of the flange between a third and a fourth hinge. By this the lock latch will be directed obliquely upwards, looked at in the direction towards the front edge of the lock latch, towards the wall supporting the lock latch, which results in a further improved holding between the lock latch and the room of an object co-operating with the locking device and intended to receive the front part of the lock latch.
According to a particular embodiment of the invention the flange has a portion which extends below the front part or the lock latch protruding from the flange. In this way the user has to withdraw the flange by means of the arm and thereby the lock latch so far that the lower part of said flange portion runs clear from an adjacent wall or edge of the object co-operating with the locking device. Thus, this additional flange portion leads to that the flange and the lock latch have to be withdrawn a longer distance than what would be the case without this flange portion, wherefore the risk that the front part of the lock latch is pressed down against the upper side of said wall or edge and by that is broken or in another way is deformed decreases.
A locking device according to the invention may be made in an integral piece and therefore may be produced in a particularly easy way, for example such as defined in the description herein. This allows the locking device to be produced from the same piece and in the same process as the closing member, such as a cap of a case or a box, which is provided with the locking device. In the case that the object, such as a case or box at which the closing member is arranged, is produced of the same material as the closing member, for example from a paperboard material, it is also possible to produce the locking device, the closing member and said object from one and the same piece and in one and the same process. Since a locking device according to the invention may be manufactured in one piece of the same material as said object this locking device is suitable to use at an object of a reusable material.
The invention also relates to a closing member, for example in the shape of a cap, comprising a locking device according to the invention and a construction, for example in the shape of a case or a box, comprising such a closing member.